Deep-focus earthquake

What is a Deep-Focus Earthquake?

A deep-focus earthquake is a special kind of earthquake that happens far down inside the Earth. Most earthquakes occur close to the surface, but these start more than 300 kilometers below the ground. They are rare and usually happen where tectonic plates come together.

Where Do They Happen?

Deep-focus earthquakes often happen along places called convergent boundaries. This is where old ocean floor, known as the lithosphere, dives beneath another plate in a process called subduction. They occur along a special slanting zone called the Wadati–Benioff zone.

How Were They Discovered?

Scientists first learned about deep-focus earthquakes in 1922 thanks to Herbert Hall Turner. Later, in 1928, Kiyoo Wadati showed that earthquakes can happen very deep inside the Earth. This helped us understand that earthquakes are not just shallow events.

Why Are They Interesting?

Studying these earthquakes helps scientists learn how the Earth’s layers move and change over time. Even though they happen deep down, they give us important clues about our planet. Deep-focus earthquakes remind us how amazing and active our Earth really is.